3D imaging of enzymes working in situ.

Today, development of slowly digestible food with positive health impact and production of biofuels is a matter of intense research. The latter is achieved via enzymatic hydrolysis of starch or biomass such as lignocellulose. Free label imaging, using UV autofluorescence, provides a great tool to follow one single enzyme when acting on a non-UV-fluorescent substrate. In this article, we report synchrotron DUV fluorescence in 3-dimensional imaging to visualize in situ the diffusion of enzymes on solid substrate. The degradation pathway of single starch granules by two amylases optimized for biofuel production and industrial starch hydrolysis was followed by tryptophan autofluorescence (excitation at 280 nm, emission filter at 350 nm). The new setup has been specially designed and developed for a 3D representation of the enzyme-substrate interaction during hydrolysis. Thus, this tool is particularly effective for improving knowledge and understanding of enzymatic hydrolysis of solid substrates such as starch and lignocellulosic biomass. It could open up the way to new routes in the field of green chemistry and sustainable development, that is, in biotechnology, biorefining, or biofuels.

Prevalence of IL-1ß +3954 and IL-1α-889 polymorphisms in the Lebanese population and its association with the severity of adult chronic periodontitis.

Pro-inflammatory cytokines, i.e., IL-1 mediate the inflammatory response and are genetically regulated in periodontal diseases. Strong association was found between the composite genotype allele 2 of IL-1ß+3954 and IL-1α-889 and severe chronic periodontitis. The aim of this study is to determine the prevalence of IL-1ß+3954 and IL-1α-889 polymorphism in a group of Lebanese individuals of homogeneous ethnicity and the possible association between genotype positive individuals and the severity of periodontal disease. One hundred and fifty-seven patients aged 53.29±13.13 years participated in the study. Subjects were classified as follows: 1) healthy subjects with no attachment loss >1mm and no clinical signs of gingival or periodontal inflammation; 2) diseased subjects with mild periodontitis (less than 15‰ of global periodontal bone loss); 3) subjects with moderate periodontitis (less than 4 interproximal sites with bone loss = or >50 percent and mean bone loss between 15 and 30%); 4) subjects with severe periodontitis (more than 7 interproximal sites with >50% bone loss and mean bone loss >35‰). Blood samples were taken and analyzed for polymorphism in the IL-1α gene at position +4845 and in the IL-1beta gene at position +3953. Statistical analysis was performed using chi-square test, Fisher Exact test, and ANOVA followed by Bonferroni multiple comparisons. The prevalence of genotype-positive subjects was 52.3‰ in the healthy control group and 42 ‰ in the diseased group. Positive genotype heterozygous of allele 1 and 2 for IL-1ß+3954 and IL-1α-889 did not represent in this study a major risk for chronic periodontitis (p=0.590). Only subjects homozygous for allele2 of the IL-1ß+3954 and IL-1α-889 were significantly more at risk for severe periodontitis with OR of 51.42.

Sinus floor elevation using a bovine bone mineral (Bio-Oss) with or without the concomitant use of a bilayered collagen barrier (Bio-Gide): a clinical report of immediate and delayed implant placement.

Xenografts have been used extensively, either alone or in combination with autogenous bone, in sinus floor elevation techniques. However, controversy exists regarding the need to cover the lateral osteotomy site with a membrane. Also, the healing period before loading remains undefined when machined-surface implants are placed. Twenty-nine patients showing reduced bone volume in the posterior maxilla had 61 Brånemark System implants placed in 30 sinuses augmented with a lateral osteotomy approach. Sinuses grafted with Bio-Oss and covered with a collagen membrane Bio-Gide (M+) received 29 implants, while grafted but uncovered sites (M-) received 32 implants. An immediate procedure was followed to place 41 implants and a staged procedure was used for 20 implants. Abutment connection was made in 2 distinct postoperative periods: 6 to 9 months and over 9 months. The patients were followed for an average of 22.4 months. The survival rate of the implants was dependent on the postoperative healing time and membrane presence. In case of the immediate procedure and in M- sites, when residual bone height was less than 5 mm, more failures occurred when the loading was done at 6 to 9 months than after 9 months. No failures occurred in the M- series when a staged approach was followed. The overall survival rate was 78.1% for the M- sites and 93.1% for the M+ sites. No failures occurred (0/35) in the control implants placed in adjacent native bone. Implant survival rate was related to the quality of the reconstructed cortical plate and to implant length. The concomitant use of a collagen barrier to cover the osteotomy site, when machined-surface implants were used in sinus grafting, seemed to improve the quality of the graft healing and survival rate of the implants loaded between 6 and 9 months after placement.

Clinical evaluation of a bilayered collagen membrane (Bio-Gide) supported by autografts in the treatment of bone defects around implants.

The aim of this study was to determine the efficacy of a bioresorbable collagen membrane (Bio-Gide) in combination with autogenous bone grafts in the treatment of peri-implant dehiscences, fenestrations, or limited vertical defects. Eighteen titanium dental implants with exposed threads placed in 17 patients were studied. Autogenous bone was used in all cases to fill the defect and maintain the space underneath the barrier. The collagen membrane was trimmed and adapted to cover the defect in a saddle configuration. The membrane absorbed the blood and easily covered and adhered to the underlying bone. It was not stabilized by any retentive means. Sixteen to 32 months postoperatively, the sites were reentered and the amount of bone regenerated was measured. The results showed significant bone gain (average 87.6%) in the treatment of peri-implant defects with Bio-Gide and autogenous bone.

Synthesis and antimicrobial activity of some novel thiazoline and thiazolidinone derivatives of 2,6-di-tertbutyl-1,4-benzoquino.

Three novel series of 2,6-di-tert-butyl-1,4-benzoquinone derivatives were synthesized: 4-[(3,4-disubstituted-2,3-dihydrothiazol-2-ylidene) hydrazono]-2,6-di-tert-butyl-2,5-cyclohexadien-1-ones, 4-[(3-substituted-5-carbethoxy-4-methyl-2,3-dihydrothiazol-2- ylidene)hydrazono]-2,6-di-tert-butyl-2,5-cyclohexadien-1-one s, and 4-[(3-substituted-4-oxothiazolidin-2-ylidene)hydrazono]-2,6- di-tert- butyl-2,5-cyclohexadien-1-ones. These compounds were prepared by cyclization of the new 4-(N-substituted thiocarbamoylhydrazono)-2,6-di-tert-butyl-2,5-cyclohexadien- 1-ones with phenacyl bromides, ethyl alpha-chloroacetoacetate and ethyl bromoacetate, respectively. Antimicrobial testing of the prepared compounds and of the key intermediate thiosemicarbazones was performed. Some of the compounds revealed higher activity than streptomycin.

Effect of surfactants on the diffusion coefficients of proteins, measured by analytical SPLITT fractionation (ASF) in the diffusion mode.

This work reports further studies of protein transport parameters in the new technique called analytical SPLITT fractionation. The SPLITT fractionation channel mimics a dialysis-like separation utilizing differential transport across an ultra-thin lamina flowing through a channel. The flowing stream is split into two sub-streams at the channel outlet, between which the protein is distributed. The cell is capable of rapidly measuring diffusion coefficients of proteins, based on their differential transport across the channel thickness, which affects the distribution between the two outlet sub-streams. The sub-stream next to the sample introduction port is more enriched than the sub-stream at the counter port when the diffusion coefficients is small. The smaller the diffusion coefficient, the higher the degree of retrieval of the protein at the sample side outlet. The entire process is realized within a short time, and a quantitative treatment of the signals of the two sub-streams yields a retrieval factor which is used for the determination of the diffusion coefficient. The conditions under which the selectivity of the diffusion SPLITT cell is optimal were examined. Analytical SPLITT fractionation has proven successful, using a number of proteins under various conditions. Results showed that the technique can detect subtle changes in proteins diffusion coefficients, and confirm that addition of small concentrations of surfactants does not change their transport parameters significantly.

[Clinical evaluation of 160 degrees C thermoplasticized gutta-percha]. / Evaluation clinique de la gutta-percha thermoplastifiée à 160 degrees C.

A clinical study involving 30 patients randomly selected in the department of endodontics at the Saint Joseph University of Beirut and in private practice was carried out. The use of "Obtura", a high-heat thermoplasticized gutta-percha system seems to be satisfactory, the findings stressed the advantages and the disadvantages of the technique and the material. Some suggestions are advanced in order to make the use of the technique easier and more efficient.

Synthesis of alkyloxybenzamide derivatives as potential antimicrobial agents.

Three series of alkyloxybenzamido derivatives have been prepared. The first comprises N1-[4-(4-alkyloxybenzamido)benzoyl]-N2-substituted alkylidene hydrazine, the second involves 1-[4-(4-alkyloxybenzamido)benzoyl]-4-alkyl, aryl, or aralkyl-3-thiosemicarbazides, and the third includes 1-substituted-5-[4-(4-alkyloxybenzamido)phenyl]-1,3,4-triazole-2-t hione. Representative samples of the prepared compounds were tested for their in-vitro antimicrobial activity.

Combined action of amoxycillin and dicloxacillin against Staphylococcus aureus in vitro.

Combination of amoxycillin (1) and dicloxacillin (2) showed synergistic bacteriostatic and bactericidal activities against 15 clinical isolates of Staphylococcus aureus, including 3 beta-lactamase-producing strains.

Ibuprofen modifies the inflammatory response of the murine lung to Pseudomonas aeruginosa.

In chronic P. aeruginosa infection, lung tissue damage is induced by either the microorganism or the inflammatory response. We investigated, in an animal model, whether a non-steroidal anti-inflammatory drug, ibuprofen, reduced lung inflammation produced by P. aeruginosa. Lung lavages, pulmonary clearance of P. aeruginosa and lung pathology were studied in CD-1 mice injected with sodium ibuprofenate. A single dose of the drug, injected immediately after 30 min exposure to the P. aeruginosa aerosol, decreased the recruitment of granulocytes into airways in a dose-dependent manner. Pretreatment with 2 doses of the drug 18 and 6 h before the P. aeruginosa challenge was even more effective. The kinetics of changes in prostaglandin E2, 6-keto-prostaglandin F1 alpha and thromboxane B2 concentrations in lung lavage fluids after P. aeruginosa aerosol were also modified by ibuprofen. Moreover, ibuprofen treatment did not impair lung clearance of the challenge microorganisms, and the animals had less inflammation of the lungs.

Hostile personality characteristics, dysthymic states and neurotic symptoms in urticaria, psoriasis and alopecia.

Three experimental groups of patients with urticaria, psoriasis and alopecia were compared for hostile personality characteristics, states of anxiety and depression, neurotic syndromes and stress with a control group of patients with other skin diseases. The patients from each experimental group were found to be less dominant, more intropunitive, more extrapunitive and more neurotic than the control group. The following neurotic syndromes differentiated the experimental groups: non-specific anxiety states in urticaria patients; neurotic depression in the patients with alopecia, and a variety of neurotic syndromes in the psoriasis patients. All experimental groups scored significantly higher than the controls in stress experienced during the year preceding the onset or the exacerbation of the illness.

Papillomavirus infection of the cervix. III: Relationship of the presence of viral structural proteins to the expression of involucrin.

Forty-two cervical biopsies with cervical intraepithelial neoplasia were compared with respect to the expression of human papillomavirus (HPV) structural proteins and the expression of the cellular structural protein involucrin, a marker of suprabasal squamous differentiation. HPV structural protein and involucrin expression displayed an inverse correlation with the severity of dysplasia. Both of these proteins were detected in 11 of 28 cases (39%) of mild and moderate dysplasia, but in only two of 14 (14%) cases of severe dysplasia. This difference was statistically significant (p less than 0.001). The presence of HPV was also associated with expression of involucrin in the full thickness of the epithelium, including the basal layer, and an altered staining pattern in the more superficial cells, particularly the koilocytotic cells. These findings support the hypothesis that squamous differentiation is required for the expression of viral structural proteins and that HPV infection begins in the basal epithelium. The study also demonstrates the utility of involucrin staining in differentiating virus-induced cytologic atypia from true neoplasia.

Immunologic studies of human schistosomiasis. I. Clinical and immunological findings in acute and chronic schistosomiasis.

Sera and ascitic fluid of 26 patients with acute and chronic schistosomiasis were studied for the presence of circulating immune complexes (CIC's), IgG, IgM, IgA, complement C3 and C4, as well as their correlation with the clinical manifestations of the disease. Serum levels of CIC's and IgG were significantly increased in patients with acute S. mansoni and S. haematobium infections and in patients with chronic schistosomiasis. Serum IgA levels were evaluated in 20% of patients with S. mansoni infection, 67% with S. haematobium infections and in 100% of chronically infected patients. Complement C3 levels were normal in all patients. Ascitic fluid analysis revealed the presence of IgG, IgM, IgA, C3 and C4 and high concentrations of CIC's. A significant positive correlation was demonstrated to occur between serum CIC's and IgG, as well as between the serum and ascitic fluid levels of CIC's of chronic patients. These findings also correlated with the degree and severity of the clinical syndrome.

Antimicrobial activity of volatile oils.

The bacteriostatic and fungistatic activities of 22 volatile oils were evaluated. The results showed that the oils tested varied in their antimicrobial activity. Cinnamon oil showed the highest activity against the tested bacteria and fungi. A comparison was made between the biostatic and biocidal activity of each oil. The results also showed that the bacteriostatic results as obtained by the agar-diffusion and serial dilution methods were not always parallel. The data obtained can be made use of clinically as well as for the preservation of liquid preparations liable to microbial contamination.

The evaluation of tiodonium chloride as an antiplaque and anticaries agent. IV. Effectiveness on plaque and gingivitis in a short-term clinical study.

The purpose of this clinical investigation was to evaluate the effectiveness of 0.3% tiodonium chloride mouthrinse on various plaque and gingivitis indices. Fifty-five subjects were randomly assigned to the tiodonium chloride or placebo mouthrinses. After a prophylaxis on day 1 of the study, the subjects suspended all oral hygiene except for the daily supervised mouthrinsing. Plaque was monitored by thickness, area, and dry weight. All mean plaque scores were significantly lower in the tiodonium chloride group than in the placebo group (P less than 0.01). Gingivitis was assessed by a clinical gingivitis index and by measuring the amount of crevicular fluid. Mean clinical gingivitis scores (GI) did not differ significantly between the two groups; however the mean gingival fluid score was significantly lower in the tiodonium chloride group than in the placebo group (P less than 0.05). No side effects were reported or observed during the study.